(a) Field of the Invention
This invention relates to a filter press and more particularly, but not by way of limitation, to a filter press used for receiving a filter bag for filtering sludge from water and dewatering the sludge in the bag.
(b) Discussion of Prior Art
Heretofore, the problem of sludge concentration has been something that has been studied for many years and to date the best solutions to the problem has been the use of belt presses, filter presses and centrifuges. Therefore there has been an ongoing need for a user friendly and simple water filter with filter press that is easy to use and still produces dewatered sludge that is acceptable for the disposal criteria demanded by current federal and state regulations. Today, current technologies require that sludge be pretreated or thickened prior to entering filter units. This type of technology requires doses of polymer or coagulant that is both costly and difficult to manage. Changes in contaminants require a new treatment scheme to cross-link the sludge and produce a filterable sludge. The water treatment industry has searched in vain for a simple treatment of sludge that will work in a variety of circumstances.
In U.S. Pat. No. 1,145,372 to Krause, a bag filter for the separation of one liquid from another is described. The invention is used particularly in steam power plants for separating oil and grease from water. In U.S. Pat. No. 722,172 to Bolz and U.S. Pat. No. 812,933 to Kiefer combination filters and presses are used for filtering different types of liquid materials. The material in the filters is allowed to drain by gravity with the remaining material in the filter compressed by a press member. In U.S. Pat. No. 4,263,330 to Streeter et al. a cheese press is disclosed. Cheese whey is deposited in the press and allowed to drain by gravity. A pressure plate is then applied to the top of the press for further draining of the whey from cheese curds. In U.S. Pat. No. 3,521,754 to Ireland a filter bag and container is described. Material to be filtered is deposited into the bag and the bag is withdrawn from the container. The bag as it is withdrawn is squeezed by a constricted top opening. In U.S. Pat. No. 5,262,070 to Ishida, a press for engaging a flexible container holding different types of blood components is disclosed.
None of the above mentioned prior art patents describe the unique combination of structure, features and advantages of the subject water/sludge filter press used with a filter bag for filtering sludge.